The present invention relates to faucets which incorporate a solenoid valve enabling the faucet to be operated by an electrical signal. In a preferred form, it relates to such faucets controlled by a proximity detector which senses the presence of an object adjacent the faucet and activates the solenoid valve.
In hospitals, public rest rooms, and other facilities, it is desirable to provide a lavatory faucet which can be turned on and off without requiring the user to touch the faucet. The prior art is replete with devices for sensing the presence of a user and in response thereto activating a solenoid valve coupled to a faucet. A common sensing technique involves transmitting an infrared light beam into a region in front of the faucet where a user may place his hands. A sensor is mounted either in or adjacent the faucet to detect the infrared light reflected by the user, thereby sensing the presence of a user in front of the faucet. In response to sensing the reflected light, the solenoid valve is opened causing water to flow from the faucet. When the detection of reflected light ceases, the valve is deenergized.
A problem with such proximity activated faucets is that an inanimate object can be left within the sensing region (e.g. by vandals) thereby causing the water to flow continuously. This activation of the faucet not only wastes water, but may result in water overflowing the lavatory if some object is also blocking the drain and overflow openings.
The previous electrically activated faucets typically incorporated the solenoid valve assembly beneath the wash basin, totally separate from the faucet. In addition, the proximity sensing circuitry was similarly housed in a separate enclosure. It is desirable in many applications of such faucets to reduce the amount of space consumed by the various components and integrate them into the faucet housing. However in doing so, it is important to be able to gain access to the different components in order to perform routine maintenance.
Other problems with the prior art related to the operating of the closure mechanism of the solenoid valve, especially in the design of the metering hole used to permit closure.